Informational devices such as telematics units are now sold with or added to many cars and other vehicles and can provide wireless communication and location-based services. These services may be accessed through interfaces such as voice-recognition computer applications, touch-screen computer displays, computer keyboards, or a series of buttons on the dashboard or console of a vehicle.
Currently, telematics units are often able to provide various types of mapping services, including driving directions, street routing, and so on. Although a vehicle telematics unit may perform many functions other than navigation, the navigational capabilities are of primary importance to many drivers. With respect to navigation, driving directions may be accessed through services that offer maps and driving directions. To use these types of services, the user may specify desired starting and/or ending addresses. Sources of routing services include off-board navigation servers, onboard data sources (e.g., databases, CDs, DVDs, etc.) and other suitable sources.
In many cases, regardless of the mechanism by which routing data is obtained, the directions may be presented in the vehicle in a visual, textual, or audio format that presents at least a portion of the route. For example, a map portion related to the user's current position may be displayed in preference to other portions of the route. Upcoming required maneuvers, such as turns or branches, may be graphically illustrated, such as by an arrow. In another example, required actions may be presented to the user verbally, where the turns are annunciated to the user as the user approaches a maneuver. In this manner, the user may follow the visual or audio directions and eventually arrive at the desired destination if all directions are followed correctly.
However, drivers may not prefer understanding only a small portion of the route at a time, since the user may want to compare the entire route to other known routes, schedule a rendezvous at an undisplayed point along the route, etc. Moreover, prior to embarking on a given route, users typically desire to preview the route to ensure that the route is direct and accurate. This is especially true of very long routes, such as cross-country routes. Current vehicle navigation units may provide route preview information for this purpose. For example, a vehicle navigation unit may provide a textual preview of the entire route or a visual preview of the entire route (e.g., via a highlighted map). However, such representations often contain a greater amount of detail than is necessary to satisfy a user's needs, and may be inefficient at concisely conveying the desired information to the driver.
A route preview system for a vehicle navigation unit is needed whereby a sufficiently informative preview of the route is given to increase driver understanding and satisfaction without increasing the driver workload.